Tiller knob



FIG. 1 is a perspective view of a tiller knob shown in an environmental state;

FIG. 2 is a top perspective view thereof;

FIG. 3 is a bottom perspective view thereof;

FIG. 4 is a side elevational view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines shown represent unclaimed subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a tiller knob, as shown and described. 